The book uses a "green" light, "yellow" light and "red" light system to serve as a shorthand for the state of civic liberty at a school drawn from students, faculty and other accounts. This "warning" system is in a sidebar for each school so it is easy to get an idea of how well tolerated political discourse, intellectual freedom, and free speech are at a school that one is considering. Perhaps you will be shocked to know that Duke University was given a red light warning for political correctness and crackpot politics prevalent in most of its departments. However, George Mason University received a yellow warning--proceed with caution--because they withdrew an invitation to speak from left-wing fimmaker Michael Moore after two Republicans in Virginia's house of delegates complained about Moore's $35,000 honorarium. So the book seems fair on both sides of the coin when it comes to the warning system.
I wish I had been given this book as a teen when looking at schools and then graduate programs. It might have led to my finding a better fit for my academic interests, political ideas, and general college milieu. Take a look at the book or give it to your teen if college is looming. It may help and it surely won't hurt for him or her to be more aware of what colleges offer in the way of political ideology, safety and student life.